The present invention relates to an apparatus for molding of tires for vehicles, especially motor vehicles. The apparatus comprises a multi-part mold defining a cavity for molding the tire. The inner surface of the cavity is determined by a split core and the outer surface by an upper and a lower mold part which are arranged coaxially with the core and which abut against opposite ends of the latter, with at least one of the aforementioned parts axially movable with respect to the others and forming in the assembled position the bead and side wall region of the tire, as well as a plurality of segments shaped to form the tread surface of the tire, whereby the segments are connected to segment carriers which are movable toward and away from the core.
In apparatus of the aforementioned kind known in the art different regions of the tire, especially the bead and side wall region as well as the tread region have been molded at separate stations. In this construction devices for transport from one to the other station are required so that these known apparatus are rather complicated and the expenditure for such apparatus is considerably high.
A decisive improvement of such apparatus has been made with a so far not published construction in which the whole tire is molded in a single station. In this construction, the parts of the mold for forming the tread region of the tire to be molded are composed of tiltable segments. These segments are mounted on segment carriers which are tangentially tiltable away with respect to the essential circular form about axes arranged below the latter. This apparatus has, however, the disadvantage that it can hardly be used for molding tires of large dimensions since the individual segments, after the molding operation, may not be tilted away from the produced tire without damaging, respectively deforming the same.
According to a further not yet prepublished suggestion, an improvement of the above-mentioned apparatus has been obtained in which the tire is likewise molded in a single station. In this construction the bead and side wall regions of the tire are molded in one operation, whereby the mold cavity in the region of the tread surface is defined by a mold part formed by a plurality of segments. Each of these segments is mounted on a segment carrier and the segment carriers are arranged about the core, whereby each segment carrier is turnable about an axis parallel to the axis of the core and carries at least an additional segment of different configuration for forming the final tread surface region of the tire. The segment carriers are movable in radial direction relative to the core and are in this construction after the first molding step moved radially outwardly and subsequently the carriers are turned about their axes so that another group of segments is directed towards the core, whereafter the segment carriers are moved inwardly in radial direction for forming the tire to its final form. This construction can be used also for molding of large tires, but it has the disadvantage to require a very large space in radial direction, especially during molding of large tires, for the mold carriers which carry two oppositely arranged segments.